Samsung's release of the 840 EVO earlier today likely prompted some questions, such as what type of flash does it employ and how does it achieve such high write speeds. Here is the short answer, with many slides in-between, starting off with the main differences between the 840 and the 840 EVO:

So, slightly increased specs to help boost drive performance, and an important tidbit in that the new SSD does in fact keep TLC flash. Now a closer look at the increased write specs:

Ok, the speeds are much quicker, even though the flash is still TLC and even on a smaller process. How does it pull off this trick? Tech that Samsung calls TurboWrite.

A segment of the TLC flash is accessed by the controller as if it were SLC flash. This section of flash can be accessed (especially written) much faster. Writes are initially dumped to this area and that data is later moved over to the TLC area. This happenes as it would in a normal write-back cache - either during idle states or once the cache becomes full, which is what would happen during a sustained maximum speed write operation that is larger than the cache capacity. Here is the net effect with the cache in use and also when the cache becomes full:

For most users, even the smallest cache capacity will be sufficient for the vast majority of typical use. Larger caches appear in larger capacities, further improving performance under periods of large write demand. Here's the full spread of cache sizes per capacity point:

So there you have it, Samsung's new TurboWrite technology in a nutshell. More to follow (along with a performance review coming in the next few days). Stay tuned!

SanDisk has done something interesting with their new Extreme II SSD series, they have used both SLC and MLC flash in the drive to attempt to give users the best of both worlds. The drive still has a DDR cache sitting between the flash storage and the controller, but there is an nCache between the MLC flash and the DDR comprised of ~1GB of SLC flash. The idea is that the SLC can quickly accumulate a number of small writes into a larger single write block which can then be passed to the MLC flash for storage. Don't think of it as a traditional cache in which entire programs are stored for quick access but more as a write buffer which fills up and then passes its self to the long term storage media once it is full. The Tech Report put this drive through their tests and found it to be a great all around performer, not the fastest nor the best value but very good in almost any usage scenario.

"With MLC main storage and an SLC flash cache, the SanDisk Extreme II is unlike any other SSD we've encountered. We explore the drive's unique design and see whether it can keep up with the fastest SSDs on the market."

If you buy a machine with an SSD installed inside of it there is a good chance it is from Toshiba and it might even be the THNSNH 256GB model. As these drives are not sold separately but only inside OEM machines it is not often benchmarked. [H]ard|OCP wants to change that and put this drive and its internally designed controller up against some of their favourite retail drives. Their testing revealed a mixed bag of performance as in some tests it came close to beating out Samsung's 840 series but in other testing ended up at the bottom of the pack. Still, as this drive will end up in many mobile devices it is good to get an idea of the performance you can expect from it.

"Toshiba's massive foundry capabilities allow it to develop some of the leading SSDs for the OEM market. These SSDs come pre-installed in the latest computers with the option for an SSD, and today we look at the Toshiba THNSNH in comparison to current top-flight enthusiast-class SSDs."

We caught wind of a leaked Intel SSD Roadmap over at VRZone. The slide shows their rough release plans into early 2014:

Starting bottom-up, the old 320 Series (cropped slide bottom) and 330 Series are being phased out in light of the newer 500 series entrants. The 335 Series, driven by a SandForce controller and 20nm flash, may drop in capacity to only an 80GB model in order to drive customers towards the new 530 Series, which will replace both of the SandForce-driven 520 (SATA) and 525 Series (mSATA) offerings. The new 530 Series will be available in 80-480GB and connect via SATA, mSATA, and the newest M.2 SATA interfaces. You can learn more about M.2 by reading the first 6 or so slides from Paul Wassenberg's presentation from Storage Visions 2013. Here's a closer look at an M.2 unit:

From CES 2013, a Micron mSATA SSD (above) and M.2 SATA SSD (below).

With the 530 appearing to become Intel's big mainstream consumer push, they will also introduce a Pro 1500 and 2500 Series. I suspect Intel's own SATA 6Gb/sec controller will be lifted from their SSD DC S3500 and S3700 Series and trickled down into the Pro Series and possibly even into the 530 Series, though that is only speculation on my part.

For the enterprise, Intel will be further juggling their enterprise models around a bit, discontinuing the SSD 710 and possibly even the (25nm) S3700 in favor of the (20nm) S3500 Series, which will also see large gains in available capacity upwards of 800GB and even 1.6TB crammed into a 2.5" SATA unit. Intel's PCIe SSD 910 will eventually be replaced by what appears to be a quad-SSD-RAID variant of the current S3500 and S3700 Series units, dubbed P3500 and P3700, respectively. These models should show a substantial gain over the SSD 910, which did not perform spectacularly when compared to the newer SATA models available.

Western Digital, along with Seagate, Toshiba, and Hitachi are working on the next step in increasing the storage density of platter based drives while HAMR is still in the works. They will be adding overlapping tracks to their platters, which they are referring to as shingles (as in the roof, not the pox). There will be two types implemented, with the first type having the shingling hidden to ensure compatibility with existing applications which might take exception to overlapping data tracks. Type two will not hide its light under a bushel and will require applications to be aware of the shingling and hopefully take full advantage of the new type of magnetic recording. According to the presentation that The Register attended we will see shingles in the near future, with HAMR due in 2016.

"Over the coming years the remaining players will be pushing traditional technology to its limits to extend the life of hard disk technology. While the industry is pretty much standardised on perpendicular magnetic recording (PMR) at present, in a couple of years there will be more fundamental hard drive technologies co-existing in the market than there are hard drive vendors."

Introduction and Specifications

Introduction:

Intel has pushed out many SSDs over the years, and unlike many manufacturers, they have never stopped heavily pushing SSD in the enterprise. They did so with their very first push of the X25-M / X25-E, where they seemingly came out of nowhere and just plunked down a pair of very heavy hitting SSDs. What was also interesting was that back then they seemed to blur the lines by calling their consumer offering 'mainstream', and considering it good enough for even some enterprise applications. Even though the die-hard stuff was left to the SLC-based X25-E, that didn't stop some consumers from placing them into their home systems. The X25-E used in this review came from a good friend of mine, who previously had it installed in his home PC.

With several enterprise class models out there, we figured it was high time we put them all alongside each other to see where things are at, and that's the goal of this particular piece. We were motivated to group them together by the recent releases of the DC S3500 and DC S3700 drives, both using Intel's new Intel 8-channel controller.

Specifications:

X25-E

SSD 320

SSD 710

SSD 910*

DC S3500

DC S3700

Capacity

32, 64GB

40, 80, 120, 160, 300, 600GB

100, 200, 300GB

400, 800GB

80, 120, 160, 240, 300, 480, 600, 800GB

100, 200, 400, 800GB

Read (seq)

250

270

270

500

500

500

Write (seq)

170

205

210

375

410

365

Read (4k)

35k

39.5k

38.5k

45k

75k

75k

Write (4k)

3.3k

23k (8GB span)

2.7k

18.7k

11k

32k

Since the SSD 910 is subdivided into 4 or 2 (depending on capacity) physical 200GB volumes, we chose to test just one of those physical units. Scaling can then be compared to other units placed into various RAID configurations. 910 specs were corrected to that of the single physical unit tested.

All other listed specs are specific to the tested (bold) capacity point.

Controllers:

Starting with the good old X25-E, which pretty much started it all, is Intel's original SATA 3Gb/sec 10-channel controller. Despite minor tweaks, this same controller was used in the X25-M, X25-M G2, SSD 320 and SSD 710 Series. Prior to Intel releasing their own 6Gb/sec SATA controller, they filled some of those voids by introducing Marvell and SandForce controllers with the 510 and 520, respectively, but those two were consumer-oriented drives. For the enterprise, Intel filled this same gap with the 910 Series - a PCIe LSI Falcon SAS RAID controller driving 2 or 4 6Gb/sec SAS Hitachi Ultrastar SSDs. Finally (and most recently), Intel introduced their own SATA 6Gb/sec controller in the form of the DC S3500 and DC S3700. Both are essentially the same 8-channel controller driving 20nm or 25nm IMFT flash, respectively.

More to follow on the next page, where we dive into the guts of each unit.